Good for: General upper-body conditioning
Balance your weight on your toes and palms, with your hands a comfortable distance apart, probably just beyond shoulder-width. Straighten your back by tucking your pelvis. Slowly lower yourself to the floor, pause, and push yourself back up. Repeat a few hundred times.
Variations: Three-point pushup (place one foot on top of the other; makes the exercise a little more challenging); decline pushup (set your feet on a bench or chair; makes it even more challenging); triceps pushup (place your hands close together, so your thumbs and forefingers touch; shifts work from chest to arms).
Good for: Athletic performance in sports involving torso rotation, such as tennis, hockey, and baseball
Assume the classic pushup position, but as you come up, rotate your body so your right arm lifts up and extends overhead. Your arms and torso should form a T. Return to the starting position, lower yourself, then push up and rotate till your left hand points toward the ceiling.
Variations: One-dumbbell (grip a dumbbell in one hand; rotate to the dumbbell side for half your repetitions, then switch the dumbbell to the other hand); two-dumbbell (grip dumbbells in both hands, and alternate sides when you come up).
Good for: Posture; midsection endurance and stability
Lie facedown, rest your weight on your forearms and toes, tuck your hips, and hold your body in a straight line from ankles to shoulders for five seconds. Do a total of 10 five-second holds.
Variations: When five-second holds are easy, progress to longer holds, until you can stay in the position for 30 seconds. Next, try a regular pushup position with your hips tucked (shown here). When you can hold that for 30 seconds, try it on your knuckles.